Development of Hole-Inside-Hole Electrical Discharge Machining Method ---Establishment of Technique for Machining a Hole on the Inside Wall of Another Hole---

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06012
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Production engineering/Processing studies
• Research Institution: The University of Tokushima
• Principal Investigator: ISHIDA Tohru 徳島大学, 大学院社会産業理工学研究部(理工学域), 教授 (20313421)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 放電加工 / 穴加工 / 穴内面穴

Outline of Final Research Achievements

Removal machining put into practical use at present cannot generally fabricate a hole on the inside wall of another hole. In other words, removal machining has the limitation for its fabricatable hole shape. To overcome the limitation, the device had been developed which can machine such a hole. However, the hole which the device could machine had short length, almost no variety of its inner diameter, and low straightness. Therefore, this study has improved the device so that it can machine the hole with longer length, a variety of inner diameters, and higher straightness. The results obtained in the experiments show that the improved device has the ability to machine the hole whose length, inner diameter, and straightness are longer, various, and higher, respectively.

Free Research Field

生産加工学

Academic Significance and Societal Importance of the Research Achievements

機械を設計するには，対象とする機械が要求された性能を発現するように，その機械の構成部品の属性（例えば，形状やその精度など）を決定する必要がある．ただし，その属性は実現できるものに限られる．具体的には，部品は一般に機械加工により製作されるため，機械加工の能力の限界を越えないものに限られる．このことは機械設計の基本であるが，同時に機械加工の能力限界が機械設計の自由度を阻害しているともいえる．この問題を解決するには，機械加工の能力限界を打破すればよい．そこで本研究では，現在の穴加工では不可能とされてきた，穴の内面に対する穴の加工を実現するとともに，加工可能な穴形状の自由度の拡張に成功した．